I'm assembling a poetry book (110 pags.) with a master page where I inserted page numbers and headers. Everything goes well until page 43. From that page on and until page 67 I have both the headers and page numbers pushed over to the left and right margins, instead of being in the middle of the page. The headers in the spread, for example, are on top on each other. This is due to invisible guides appearing in the middle of the pages. They are not in the master pages. I have no idea how they got there. I tried to get rid of them but they don't move.